Hsp27 is a molecular chaperone that is constitutively expressed in several mammalian cells, but particularly in pathological conditions. In addition, these proteins share anti-apoptotic properties and are tumorigenic when expressed in cancer cells. Hsp27 expression is associated with a poor prognosis in virtually all cancer forms such as leukemias, breast, gastric, liver, and prostate cancer, and osteosarcomas. Increased Hsp27 expression may also predict the response to some anticancer treatments. For example, expression of Hsp27 is implicated in resistance to chemotherapy in breast cancer and predicts a poor response to chemotherapy in leukemia patients.
Besides cancer modulation, the expression of Hsp27 proteins have also been considered to be of importance for treatment of myopathies and asthma.
Oncogenex are developing an antisense oligonucleotide which targets the Hsp27 mRNA—referred to as the OGX-427 antisense compound. WO2007/025229 and U.S. Pat. No. 7,101,991 disclose antisense oligonucleotides which target Hsp27.
There is a need for improved antisense oligomers targeting Hsp27.